(DrEddyClinic News) Heavy gum chewers risk breaking down the amalgam in their dental fillings and having dangerously high levels of mercury in their blood and urine as a result, a study published in the Stockholm newspaper Aftonbladet on Friday said.

The study was undertaken by the Sahlgrenska university hospital in Gothenburg, west Sweden.

"In our study we found out that people who chewed gum for at least five hours per day had significantly higher mercury levels in their urine and blood," medical researcher Gerd Saellsten was quoted as saying.